Optical waveguide sheath

ABSTRACT

The illumination system is a cannula comprising a transparent or semi-transparent material capable of carrying light from the proximal end of the cannula to the distal end of the cannula, thereby illuminating a surgical field. The surgical field is thus illuminated through components that do not occupy space that may otherwise be used for optics and or surgical tools. The illumination source may be optically coupled with the cannula at any appropriate location. The cannula comprises a sterilizable polymer which functions as a waveguide. A waveguide is a material medium that confines and guides light. When in use, the light source connected to the hub provides light which may be guided to the distal end of the cannula or any other suitable location. Thus, the sheath provides structure-guided illumination resulting in the illumination of the surgical site.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/412,764 (Attorney Docket No. 40556-705.301), filed Mar. 27,2009, which is a continuation of U.S. patent application Ser. No.11/397,446 (Attorney Docket No. 40556-705.201, now U.S. Pat. No.7,510,524), filed Apr. 3, 2006, which claims priority from U.S.Provisional Patent Application Nos. 60/668,442 (Attorney Docket No.40556-705.101), filed Apr. 4, 2005 and 60/724,717 (Attorney Docket No.40556-706.101), filed Oct. 7, 2005, the full disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of surgicalillumination and more specifically to optical waveguide endoscopeillumination.

2. Background of the Invention

Currently optical fiber illumination elements such as element 12 shownin FIG. 1 are used exclusively in medical illumination where smallpackaging is critical. Devices such as endoscope 10 are the most commondevices that currently use optical fiber illumination. Due to itscompact size, optical fiber is an excellent choice for rigid endoscopeillumination. However, there are complications using optical fiberillumination in flexible endoscope applications.

Although the cost of raw glass or plastic fiber is relativelyinexpensive, the cost of assembling the fiber into an endoscope tube maybe high. Once the fiber is inserted, it generally must be glued andpolished to a specific angle.

Optical fiber is extremely fragile and brittle. During the assemblyprocess or in the field after many sterilization cycles, optical fibermay start to break down and degrade. Color change is also very commonwith fiber optics after many sterilization cycles. Since the fiber isintegrated into endoscopes, any damage to the fiber optics also resultsin damage to the scope, thus causing an expensive overhaul.

A significant challenge in many endoscopic procedures is cablemanagement. There may be many cables typically present in the sterilefield; camera cable, fiber optic cable, irrigation and suction, etc.Since the optical fiber cable has the largest diameter it typically isthe heaviest cable. One of the challenges that face surgeons using rigidendoscopes is constant rotation of the endoscopes to view differentorientation angles. When the endoscopes are rotated, the fiber opticcable is forced to rotate around with the endoscope, thus causinginterference. These issues become even more important duringarthroscopic surgery. Since the optical fiber cable is heavy, it willactually rotate the endoscope, often forcing the surgeon to keep one oftheir hands on the fiber optic cable to prevent unwanted spinning of theendoscope.

The illumination fiber also occupies space inside an endoscope or othersurgical implement. By allocating space to optical fiber illumination,the diameter of optics may be limited to maintain the smallest overallendoscope diameter.

What is needed is a multifunctional surgical illumination device.

BRIEF SUMMARY OF THE INVENTION

The illumination system described below comprises an arthroscope,endoscope or other suitable surgical tool and an attachable cannula orsheath comprising a transparent or semi-transparent material capable ofcarrying light from the proximal end of the cannula to the distal end ofthe cannula, thereby illuminating the surgical field. The surgical fieldis thus illuminated through components that do not occupy space that mayotherwise be used for the optics of the arthroscope. The arthroscopicillumination system further comprises one or more illumination sourcesdisposed at the proximal end of the cannula. The illumination source maybe optically coupled with the cannula at the hub or other appropriatelocation. The cannula comprises a sterilizable polymer which functionsas a waveguide. A waveguide is a material medium that confines andguides light. When in use, the light source connected to the hubprovides light which may be guided to the distal end of the cannula orany other suitable location. Thus, the sheath provides structure-guidedillumination resulting in the illumination of the surgical site.

An optical waveguide according to the present disclosure may be a singleuse disposable sheath that surrounds an endoscope or other suitableapparatus to conduct illumination to the distal end of the apparatus.The optical waveguide sheath may also introduce irrigation and orprovide suction along the apparatus. Separating illumination from theendoscope permits increasing the aperture of endoscopes withoutincreasing the overall dimension of the endoscope.

An optical waveguide sheath or tube according to the present disclosureprovides a flexible waveguide suitable for medical applications. Theoptical waveguide may be separate and independent of an endoscope orother medical device and for example may be oriented coaxial to aflexible or rigid endoscope to provide light for the endoscope or othersurgical device. The optical waveguide may include suitablemicro-structure or structures to keep the light bouncing within thewaveguide independent of the outside medium or the curvature of thewaveguide. The waveguide may be disposable and may be sized toaccommodate an endoscope or other device within the bore, therefore theoptical fiber labor component in manufacturing of endoscopes or otherilluminated devices may be eliminated.

In a first aspect, the present disclosure provides a waveguide as asingle unit that may be molded into custom shapes and or made single usedisposable. If the waveguide is single use and sold sterile, it will bebrand new for every application, so if any damage occurs during aprocedure, the waveguide may be easily replaced and may be discardedafter a procedure.

In another aspect of the present disclosure an optical waveguide mayalso operate as a cannula providing irrigation and or suction or othersuitable services for medical applications.

The rotation issues previously faced with fiber optics may be resolvedwith an optical wave-guide because the waveguide can be designed to havea rotating ring into which the fiber optic cable is connected from alight source. Thus the waveguide can spin independently with the scopewithout having a need to rotate the tethered fiber cable.

In most endoscopic applications a sheath is used for suction andirrigation. This sheath fits over the endoscope. If the sheath was anoptical waveguide, it may simultaneously provide suction and orirrigation as well as illumination. Since the optical fibers areeliminated from the bore of the endoscope, the optics may bemanufactured to a larger diameter, thus dramatically increasing theresolution of the scope. Therefore, the overall diameter of theendoscope will not change, and the resolution will be increased.

An optical waveguide may provide illumination and at the same timeperform as a surgical instrument. Other than rigid endoscopes, devicessuch as trocars, obturators, retractors, may all be made from waveguidematerial. Devices, such as laryngoscope blades can be make our ofwaveguide material and thus be self illuminating thus eliminating anyneed for fiber optics.

In another aspect of the present disclosure one or more coupling lensesmay be used to couple light into an optical waveguide. The lenses orother suitable structure may adopt any suitable geometry such as forexample spherical, cylindrical, aspherical and or non-symmetricalgeometries. If a light source having a wide output angle such as one ormore LEDs is used, a more complex lens system such as an asphere may beused to optimize light coupling.

In another aspect, one or more faces of an optical waveguide may includea predetermined micro structured pattern. Different optical light outputshapes may be achieved by creating specific structured surfaces orpatterns.

It is also possible to apply the structured technology to deflect lightas well as focus it into a particular shape. Microstructure may beapplied to the back and or the front of a refractive element to deflectthe beam as well as shape it. Microstructure surfaces may also becombined with one or more air gaps and or conventional surface shapingto achieve desired optical performance.

In a still further aspect of the present disclosure one or more surfacesin an optical waveguide sheath or adapters or connectors may bepolarized using any suitable technique such as micro-optic structure,thin film coating or other. Use of polarized light in a surgicalenvironment may provide superior illumination and coupled with the useof complementary polarized coatings on viewing devices such as camerasor surgeons glasses may reduce reflected glare providing less visualdistortion and more accurate color resolution of the surgical site.

A surgical illumination system according to the present disclosure mayinclude a generally cylindrical light waveguide having a bore sized toaccommodate one or more surgical instruments, an illumination source, anillumination conduit for conducting illumination energy from theillumination source, and an adapter ring for engaging the illuminationconduit and coupling illumination energy from the illumination conduitto the light waveguide, the adapter ring permitting relative movementbetween the illumination conduit and the light waveguide.

An alternate illumination system according to the present disclosure mayinclude an illumination source, a generally cylindrical light waveguidehaving a distal end and a proximal end and a bore sized to accommodateone or more instruments or tools extending from the proximal end throughthe distal end, the waveguide conducting illumination energy from theproximal end to the distal end and projecting the illumination energyfrom the proximal end, and an illumination conduit for conductingillumination energy from the illumination source to the proximal end ofthe light waveguide.

These and other features and advantages will become further apparentfrom the detailed description and accompanying figures that follow. Inthe figures and description, numerals indicate the various features ofthe disclosure, like numerals referring to like features throughout boththe drawings and the description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the distal end of a conventionalendoscope.

FIG. 2 is a perspective view of the distal end of an endoscope with anoptical waveguide sheath according to the present disclosure.

FIG. 3 is a perspective view of the distal end of an optical waveguidesheath according to the present disclosure.

FIG. 4 is an end view of the distal end of an optical waveguide sheathaccording to the present disclosure.

FIG. 5 is a side view of an optical waveguide sheath coupling to fiberoptic elements.

FIG. 6 is an end view of the fiber optic coupling lens array of FIG. 5.

FIG. 7 is a side view of an optical waveguide sheath with a lightcoupling adapter according to the present disclosure.

FIG. 8 is a side view of an optical waveguide illumination system with ahigh-resolution arthroscope disposed therein.

FIG. 9 is a side perspective view of an alternate optical waveguidelight coupling technique.

FIG. 10 is an end view of the optical waveguide of FIG. 9.

FIG. 11 is an end view of an optical waveguide with another alternatelight coupling.

FIG. 12 is a cutaway view of the proximal end of the optical waveguideof FIG. 11 taken along A-A.

FIG. 13 is a cutaway view of the proximal end of the optical waveguideof FIG. 11 taken along B-B.

FIG. 14 is a cutaway view of an alternate optical waveguide.

FIGS. 14 a-14 d are cutaway views of alternate distal ends of theoptical waveguide of FIG. 14.

FIG. 15 is a perspective view of an optical waveguide with an alternatelight coupling.

FIG. 16 is a cutaway view of the proximal end of the optical waveguideof FIG. 15.

FIGS. 17 a-17 c are front views alternate distal ends of the lightcoupling of FIG. 15.

DETAILED DESCRIPTION OF THE INVENTION

The following disclosure generally refers to an optical waveguide andassociated elements for conduction of light. This discussion is forexample and the following disclosure may also be suitable for anyelectromagnetic radiation. The cross-sections illustrated are generallycircular and may also adopt any suitable geometry.

Referring now to FIG. 2, optical waveguide system 14 may accommodate anysuitable surgical instrument such as endoscope 18 which is encased,enclosed or otherwise surrounded by optical waveguide sheath 16. Anoptical waveguide sheath according to the present disclosure is agenerally annular or cylindrical shaped structure and may bemanufactured separately and may be a single use device. In the event ofa failure of an optical waveguide such as optical waveguide sheath 16, areplacement may be introduced immediately. Flow path 26 is createdbetween endoscope 18 and optical waveguide sheath 16. Flow path 26 maybe used for any suitable service such as suction, irrigation or theintroduction of other tools or devices.

Surgical devices such as endoscope 18 may be made without anillumination element and thus aperture 20 may be increased withoutincreasing overall dimension 30 compared to dimension 11 of the deviceof FIG. 1. Wall 18A of endoscope 18 may also be perform as opticalwaveguide to improve illumination and may provide an alternate lightpath to enable illumination of different characteristics.

Referring now to FIG. 3, waveguide sheath 28 may be a single generallyuniform element, it may be composed of two or more distinct illuminationpathways forming an apparently singular conduit, or it may be composedof one or more parallel light conducting elements such as light pathelement 24 or light path element 92 of FIG. 14. Moving the illuminationelement from conventional endoscopes to a separate device such as alight conduit such as waveguide sheath 28 permits illumination surface22 to be larger than many conventional illumination elements.Surrounding an apparatus such as an endoscope with the optical waveguidemay provide generally uniform illumination for any orientation of theendoscope or other device.

Referring now to FIG. 4, illumination surface 22 may adopt any suitableconfiguration to provide illumination. For example facets such as facets30 may direct light energy in any selected direction and may be coatedor otherwise treated to introduce filtering for frequency and orpolarization. Microstructures such as microstructures 32 may be used toachieve directed light energy, filtering or other. One or more lensstructures may be coupled to illumination surface 22, or they may beformed in or on illumination surface such as lenses 34. Alternatively,these elements may also be combined.

Using separate light conducting elements such as light path elements 24may permit selective illumination through a waveguide sheath as well asprovide multiple illumination paths for illumination having differentcharacteristics such as polarization, wavelength or intensity. Eachlight path element may include microstructures, facets, lenses or othersuitable treatment on distal face 24A.

In FIGS. 5 and 6 coupling ring 38 is provided to couple light fromfibers 42 into optical waveguide 36. Coupling ring 38 permits rotationof optical waveguide 36 about bore centerline 37 without rotating fibers42. Coupling ring 38 may include any suitable light coupling structuresuch as coupling lenses such as lenses 40, each lens coupling lightenergy 39 from a fiber 42 into optical waveguide 36. The lenses orsuitable microstructure may be spherical, cylindrical or aspherical ornon-symmetrical depending on the light source. In the case of fiberoptics, a spherical lens may be used to match the numerical apertures(acceptance angle) of the fiber optic and the optical waveguide. Becausea specific cone angle of light exits a fiber optic cable, a matchingacceptance angle should be used for the coupling ring.

Referring now to FIG. 7, light coupling adapter 44 may be used to couplelight energy from light conduit 43 in through face 46 and directs thelight energy around access channel 48 and through adapter ring 50 intooptical waveguide 36. Access port 49 and access channel 48 provideaccess to bore 35 for any suitable surgical tool, apparatus or device.Adapter ring 50 engages waveguide 36 while permitting relative motion ofwaveguide 36 relative to light coupling adapter 44. Alternatively,coupling adapter 44, adapter ring 50 and optical waveguide 36 may becontiguous with no relative motion permitted. Coupling ring 50 may alsobe an element of waveguide 36 as well as an element of light couplingadapter 44.

FIG. 8 illustrates arthroscopic illumination system 52 with ahigh-resolution arthroscope 54 disposed therein. The arthroscopicillumination system comprises a cannula sheath 55 adapted to providestructure-guided illumination, a hub 56 and an illumination source 58.The hub may contain one or more valves 60 and be placed in fluidcommunication with a vacuum and/or irrigation source 62. The cannulasheath 55 comprises a biocompatible sterilizable polymer that functionsas a waveguide. The polymer may be transparent or semi-transparent andmay incorporate facets, prisms, microstructures or other suitablecharacteristics.

An illumination source is operably coupled to the hub 56 and placed inoptical communication with the cannula sheath 55. The illuminationsource comprises one or more LEDs 64 (light emitting diodes), a powersource 66, a conductor 68 electrically connecting the power source andthe LED, an LED control circuit 65 and switch 67. The LED is preferablya white-light LED, which provides a bright, white light. The powersource may be provided in any form such as a power outlet or a lithiumion polymer battery. When the illumination source is illuminated, lightfrom the illumination source propagates through the cannula sheath bymeans of total internal reflection, illuminating the distal end 69 ofthe cannula sheath. Light does not leak out of the outer diametersurface of the sleeve. The outer surfaces of the sleeve may be providedwith metallic or other suitable coating to help prevent light leakagewhile assisting with total internal reflection. The distal end of thesleeve may be provided with a microstructure, optical component or adiffuse finish. Based on the desired optical output, a molded componentor custom finish may be applied to filter or shape the light exiting thesheath.

Alternatively, the illumination source may comprise a conventional fiberlight cable operably connected to the hub. The illumination source maybe placed in optical communication with the sheath through opticalcoupling lenses disposed on the proximal end of sleeve 61 within hub 56.

Referring now to FIGS. 9 and 10, light energy from LED array 72 may becoupled into optical waveguide 70 using reflective and or refractiveoptical assembly 74 in proximal end 70 p such that light energy isprojected from illumination surface 71 on distal end 70 d.

FIGS. 11, 12 and 13 illustrate an alternate light coupling into opticalwaveguide 76. Light 75 may be provided through any suitable conduit suchas plastic rod 78. Light conduit 78 may be formed, cut or otherwiseshaped at engagement end 79 to reflect light 75 at any suitable anglerelative to light conduit 78. Surface 80 may include any suitabletreatment, coating or microstructure to reflect a suitable amount oflight 75 at a suitable angle relative to light conduit 78.

A notch, groove or other suitable indentation such as u-shaped notch 82may be provided in proximal end 84 of an optical waveguide to engage alight conduit such as plastic rod 78. The shape of notch 82 may beselected to optimize light coupling between the light conduit and theoptical waveguide. One or more structures such as facet 86 may beincluded in any suitable location of an optical waveguide to reflectlight into bore 88 or out of the optical waveguide into areassurrounding the waveguide. Light generally exits optical waveguidethrough illumination surface 89.

Alternatively, optical waveguide 90 as illustrated in FIGS. 14 and 14a-14 d may be formed using one or more solid light guides such as lightpath element or rod 92 and forming the one or more rods into a springlike spiral. Input 93 may be formed at any suitable angle 94 with anoptimal angle between 45° and 90°. Distal end 95 may be cut or formed tohave any suitable configuration to reflect or emit light in any suitabledirection or directions as illustrated in FIGS. 14 and 14 a-14 d forexample.

Surgical illumination system 100 may include optical waveguide 96 andlight adapter 98. Distal end 99 of light adapter 98 may have anysuitable shape as illustrated in FIGS. 17 a-17 c. Lenses or otheroptical structures such as lenses 102, 104, 106 and 108 may have anysuitable shape or orientation to optimize light coupling or output.Different lenses may also be combined on a light adapter as in FIG. 17a. A complimentary surface 110 may be produced in optical waveguide 96to achieve selected light transfer or coupling. Alternatively, lightadapter may extend through optical waveguide 96 such that lenses such aslenses 102, 104, 106 and or 108 directly illuminate bore 105 and or thesurgical site.

An optical waveguide may also be used with any suitable end cap engagingthe distal end of the optical waveguide. The end cap may or may not beused to modify or reflect the illumination energy. Similarly, shims maybe used within the optical waveguide to orient any tool or tools withinthe waveguide and the shims may or may not conduct or modify theillumination energy.

Thus, while the preferred embodiments of the devices and methods havebeen described in reference to the environment in which they weredeveloped, they are merely illustrative of the principles of theinventions. Other embodiments and configurations may be devised withoutdeparting from the spirit of the inventions and the scope of theappended claims.

1. A surgical illumination system comprising: an illumination source;and a single generally cylindrical non-fiber optic light waveguideformed of homogeneous uncoated material having a distal end, a proximalend, an open bore extending therebetween, a plurality of opticalstructures adjacent the distal end, and an illumination conduit forconducting light from the illumination source to the proximal end ofwaveguide, wherein the bore is sized to receive one or more instruments,and the waveguide conducts the light from the proximal end to the distalend by total internal reflection, and wherein the plurality of opticalstructures extract the light from the waveguide and direct the lighttoward a surgical field.